Polymeric photoinitiators as a tool for clarifying mechanistic aspects of free-radical polymerization

Polymeric photoinitiators, based on side-chain benzoin methyl ether moieties differently anchored to the backbone, have been designed and applied to the UV cure of acrylic formulations for clarifying the role played by benzoyl and alpha-alkoxybenzyl primary radicals in the polymerization process. Kinetic data on the photocuring processes, in the presence of the above polymeric systems, as compared with those obtained by using the corresponding low-molecular-weight structural models, are presented and interpreted in terms of different reactivity of the two types of primary radicals towards initiation and termination steps of the polymerization process.